I’ve always thought that pupils learn best through practical enquiry. By developing programmes of study that require investigation, students develop the skills necessary to accompany the knowledge too. This is backed up by research into learning retention rates:

But you’ve said it is backed up by research by the NTL. They themselves admit that they have no provenance for the ‘evidence’ as they can’t trace it (Magennis and Farrell, 2005). And Dale’s Cone of Experience has been entirely debunked as having no basis in evidence. http://www.willatworklearning.com/2006/05/people_remember.html